Young women with lower levels of vitamin D were more likely to have clinically significant depressive symptoms."Depression has multiple, powerful causes and if vitamin D is part of the picture, it is just a small part," said David Kerr from the Oregon State University and lead author in a paper published in the journal Psychiatry Research.

Vitamin D is an essential nutrient for bone health and muscle function and its deficiency has been associated with impaired immune function, some forms of cancer and cardiovascular disease."I think people hear that vitamin D and depression can change with the seasons, so it is natural for them to assume the two are connected," added Adrian Gombart, associate professor of biochemistry and biophysics from the university.

For the study, researchers recruited 185 college students, all women aged 18-25.Vitamin D levels were measured from blood samples and participants completed a depression symptom survey each week for five weeks.